Myth 1: A Breast Lump Is Probably Cancer

Most breast lumps women feel -- 8 out of 10 -- aren't cancer. It's more common for them to be a cyst (a sac) or a fibroadenoma (an abnormal growth that's not cancer). Some lumps come and go during a woman's menstrual cycle.

You can't tell what it is by how it feels.

"It's always important to know your own body and detect a change which may need to be evaluated," says Beth Overmoyer, director of the Inflammatory Breast Cancer Program at the Dana-Farber Cancer Institute in Boston. "If it is cancer, then you may have saved your life."

Myth 2: If You Have a Lump but Your Mammogram Is Normal, You're Done

You may need more tests, such as an MRI, ultrasound, or follow-up mammogram, to take another look at the lump.

You may also need to get a biopsy, which is when a doctor takes a small sample of the lump to test it.